Friday, April 18, 2014

“Breakthrough Cures”? Reasons for Skepticism

Earlier this week I posted about the current issue of the New England Journal, and mentioned in
passing the appearance of antiviral drugs for hepatitis C that are being touted
as new miracle cures. My focus in that post—http://brodyhooked.blogspot.com/2014/04/summarizing-market-failure-special.html
--was how our so-called free market fails to protect the
public interest, so I looked only at the outrageous cost of the hepatitis C
drugs and gave a free pass, more or less, to the “cure” claims.

In doing so I overlooked an older and a more recent blog
post by our good pal Dr. Roy Poses at Health Care Renewal:

Dr. Poses takes care to show the extraordinarily flimsy
evidence on which these new drugs are being ballyhooed. He says a number of
things about study design and so on, all of which seem pertinent. But if we try
to get a sense of the big picture, all I think we need to know is the natural
history of hepatitis C. As Dr. Poses reviews for us, hepatitis C can be a very
bad disease leading to liver failure and death. But the total number of folks
with the virus who end up with this extreme version of the disease is not that
large. A goodly number of people who carry the hepatitis C virus never develop
any obvious disease at all. Another good chuck of them develop some liver
inflammation, but it never develops into the extreme life-threatening forms.

So before one can get all that excited about a new treatment
for hepatitis C, insofar as actual patient-centered outcomes are concerned,
we’d need a large-scale follow-up study that showed that people getting the new
drugs actually had improved health over the long haul. That would in turn
depend on showing that the apparently decent (but hardly perfect) side effect
profile of the new drugs is maintained long-term, else the chance of having a
bad side effect might be as great as the chance one would have had the bad kind
of rapidly-advancing hepatitis C infection with liver damage.

According to Dr. Poses who’s checked out the literature much
more carefully than I have, what we know so far is that the new drugs do a
pretty good job of clearing the hepatitis C virus from the bloodstreams of
patients when followed for a period of up to 24 weeks.

It may well be that a drug that does this good a job of
clearing the virus in the short term does an equally good job of saving the
patient from long-term, serious consequences of having the virus. Or that may
not be the case—we’ve seen many, many instances of initially promising
treatments that ultimately fail to pass that test. (This may also be a good
time here to remind ourselves of Dr. John Ioannidis’s warning:

Now, let’s be fair to the advocates for the new drug. It
will take years, to say nothing of tons of money, to do the studies needed to
show the real effectiveness of these new hepatitis C drugs. So in the meantime,
the data we have so far is probably what’s to be expected at this stage. And so
far, the drug is performing more or less as one would expect if indeed it is
going to turn out to be a breakthrough drug.

OK, I’ll buy all that. So how about some recognition of the
actual limitations of what we know, when this drug is being talked about? Why
should supposedly scientifically-aware advocates for the drug feel a need to talk
like used car salesmen? (Unless, in fact, their ultimate goal is to sell us a
clunker?)

So mea culpa for
my earlier post, if I inadvertently added to the hype around these new drugs,
instead of joining Dr. Poses in raising the appropriate skeptical concerns. One
can hope that the drugs turn out to be what they are hoped to be; and one can
also hope that somehow, if that’s the case, people who need them will be able
to afford them.